Cushion-tire for vehicle-wheels.



E. J. DUFF.

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. 912,943. E Patented Feb. 16, 1909.

has.

f 6 coung vent j certain new and useful Im rovements; in Cushion-Tires for Vehicle-Vdheels,

and of which the following is the specification.

' 50 tires.

-' practically all the attributes of a pneu- To tvhom it may'comem:

of Lancaste'r, England have in- Var' ious attempts have been made to A 10 secure in tires greater resiliency than that given by solid rubber, and, at the same 1 time, to avoid the disabilities inherent in the -pneumaticvar1et l;. What are known as av cushion tires e been formed with various forms of hollow areas within them,

some surrounded by rubber, others archlike and others in which there were a plurality of hollow spaces.

A- titer-made according to the present invention belongs to the last mentioned r class, but in it t I e parts and. areas are proportioned to give certain specific results ereinafter exp ained:

Essentially the tire in. cross section is .parallelogrammic with the tread at one acute angle a the rim at the other acute an le of the parallelogram, while the obtuse ang es arejoined by a tensional member. That is to say, there are formed in the tire two hollows of substantially triangular section theupper, base down; the lower, base up. Surrounding these apertures are masses of rubber the median lines of whose areas form a parailelogram joined at its obtuse angles 55 by a horizontal line.

The rubber areas or members are sufficiently substantial to resist lateral deformation so that they, with the exception of the horizontal tensional member, are subjected 40 solely to complression.

Owing to t e parallelogrammic form the members act as double toggles controlled by the tensional member midway between their f'ulcra which are at rim and tread.

The tire therefore offers a resistance which does notincrease with the rapidity of a solid rubber tire under load, and, on the other hand, does not deform suddenly as do the maority of arch-like or other hollow he improved tire therefore has matic tire without its liability to puncture and bursting and at a lower cost.

.In order that the invention and the man- Specification '0: Letters Patent. Application filed July 24, 1901. Serial it. seem.

I EDWARD JAMES DUFF,-OF LIVERPOOL, ENGLAND.

cosmos-Tran Fee vssicna wnnsas;

Patented Feb. 16,1900.

ner of performing the same may be'preiperly understood, there is hereunto a pen d a sheet of ex lanatory drawings s owing in section in roved form of tire, and in s. 2 and 3,

iagrams of the action of the parts of that tire under load.

In this example, as has already been explained, the tire consists of four members, A,'B, C, D, together forming a parallelogram with its acute an 'les disposed verticall one at the tread, the other at the rim,

1 re. 1 an exam'le of the .im-

A fifth and tensional member,-G, connects the obtuse angles of the members, A, B, C, D, and divides the central hollow into two triangular spaces, H, J.

As explained by the diagram Fig. 2, showing the tire under normal load in which arrows substantially median to the members indicate the lines of force under normal load, the forces, K, L, of load and upward resistance equal and op osite, are each split into two, M, N, and O, D, median to the parallelo ram members. The forces M and 0 comine to form the force R, while the forces N and P combine to form the force S.

It will be seen that M, N, O, P, are comressional in the parallelogram members, A, C, D, (Fi 1) and that R, S, are jointly tensional in t e member, G.

As shown in Fi 3, since the forces of com pression, M, N, 5, P, act upon the median nes of the parts through which they pass,

these parts are in direct compression at all times and do-not become distorted laterally as do the walls of circular or arch-section tires, and thus the resistance they odor is at all times commensurate with the load. In addition, the tensional member, G, retains the members, A, B, C, D, against undue spreading or flattening and adds its tensional resistance to the-com ressional re sistance of the members, A, B, l), C.

As the outer members of the tire are at all times in compression its surface is much less liable to be out.

It will further be seen that as the load thrown u on the tire by road inequalities increases, t e effort to compress the compression members increases in enhanced ratio as does also the tension in the tensional part thus the period of elasticity is very greatly enhanced ever known forms. 4

It is to be understood'that the tread part may be of any desired form and that the u any suitable member joining the obtuse an les, the legs of said parallelogram being of su stantially the samelength and strength and producing a double toggle action with relation to said horizontal member, substantially as described.

2.A cushion tire V essentially parallelogrammic in cross section with the acute angles Vertical and having a horizontal tensional member joining the obtuse angles, the legs of said parallelogram being of substantially I uniform matenal and strength and producing a double toggle action with relation to said horizontal member, substantially as described.

- 3. A cushion tire essentially parallelogrammic in cross section with the acute angles vertical and having a horizontal tensional member joining the obtuse angles, said tire being so formed internally and externally that the legs of the parallelogram are substantially straight so as to produce a double toggle action with relation to said horizontal member, substantially as described.

In testimony whereof I have signed my name to this specification, in the presence of two subscribing witnesses.

- EDWARD JAMES DUFF.

V Witnesses:

JILLIAM Towns, RALPH GIBBS. 

